Abstract: Apparatus comprising a combustion engine having a combustion zone for burning acetylene with an oxygen-containing gas to produce mechanical power and exhaust gases including H.sub.2 O and oxides of carbon, fuel input means, exhaust output means and power output means; a first structure defining a reaction zone containing a compound selected from the group consisting of sodium peroxide, potassium peroxide, lithium peroxide, sodium superoxide, potassium superoxide and lithium superoxide for reacting H.sub.2 O with the compound to produce oxygen and for reacting oxides of carbon with by-products of the reaction of the H.sub.2 O with the compound; a first conduit connecting the exhaust output means to the first structure for supplying exhaust gases, including H.sub.2 O and oxides of carbon, thereto; a second conduit connecting the first structure to the fuel input means for supplying oxygen thereto; a second structure defining a reaction zone containing calcium carbide for reacting H.sub.